The Democracy of the founding fathers was Greek Democracy, predicated upon a slave society, and restricted to only the elite. This is the society we live in today, even with our reforms towards direct representation. The system is inherently biased towards the election of elites and against the representation of the masses. Hamilton called it “faction” when the working class got together and demanded better conditions, and mechanisms were built in (which still exist to this day) that serve to ensure the continued dominance of the elite over the masses. The suffering of the many is intentional. The opulence of the wealthy is also. This is the intended outcome.
That’s the excuse people always give. Human nature is a lot of things. Greed, avarice, jealousy, definitively part of that. Just as much a part though, are empathy, caring, and selflessness. Human nature isn’t a fixed predetermined set of rules. If it was, there would be no variability in humanity whatsoever. Human nature as used here is just another thought terminating cliche designed to stop intelligent conversation.
The material conditions within a given society determine the most likely expressions of human nature within that society. Of course a society structured around elevating greed, violence, misogyny, etc, would see that reflected in its institutions and among its people. Materialism is a science, “human nature” is pop culture.